Safety switch



E. M. WARREN SAFETY SWITCH Feb. 6, 1951 2 Sheets-Sheet l awe/MM ZskZ/Zffizrran Filed June 30, 1947 ammo-,

E. M. WARREN Feb. 6, 1951 SAFETY SWITCH 2 Sheets-Sheet 2 Filed June 50, 1947 Patented Feb. 6, 1951 UNITED STATES PATENT OFFICE 2,540,974 sAFE'rY swabs Estel M. Warren, Clinton, N. 0. Application June 30, 194"}, Serial No. 758,117

W 2 cases.

t V 1 V This invention relates to a safety switch for mounting on a vehicle, such as a tractor or the like, which will stop the operation of the engine when the vehicle tilts to a predeterminedangle. In the operation of tractors or like vehicles,

on hilly ground or on level ground when the vehicle is under heavy pull, the tractor may turn backwards and upside down, or may roll over .due to the angle of the tractor, and this results in both damage to the tractor and possible in jury to the operator. It is an object of this invention to provide an improved t lt switch for mountin on the tractor and connection with the ignition circuit which will ground theignitio n circuit and in this manner stop the engine before the tractor tilts beyond a predetermined dangerous angle.

U Another object of this invention is to provide a safety switch of this kind which is simple in construction and is normally inoperative, but is 2' gravity operated when the tractor tilts.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more 'par- 1 ticularly pointed out in the appended claims.

In the drawings, Figure 1 is a detail side elevation of ajsa fety switch adapted to be mounted on a tractor or other vehicle. constructed according to an em- :.I.

bodiment of this invention, I

I Figure 2 is a sectional View, partly diagrammatic, taken on the line 2-2 of Figure l,

Figure 3 is a sectional view taken on the line 3-3 of Figure 2,

Figure 4 is a sectional view taken on the line J secured to a rear end wall 54 by fastening menu bers I3, and to a front wall byfastening members l6. t H N The front wall 15 forms, with the \/-shaped bottom wall I I, a track or guide I? within which a switch operating sphere 18 is adapted to loosely engage. The-housing It also includes a pair of vertical walls is at the opposite ends of the guide I1, and a pair of enclosed switch members generally designated as 20 are secured to the vertical walls I9.

I A rear switch 2|, similar to the switch 20, is secured and extends from the rear wall i l Each switch comprises a sleeve 22 within which a movable contact 23 is mounted. The contact 23.is secured to a shank or shaft 24 which is slidable in an inner sleeve 25 carried by the sleeve or housing 22. A washer 25 is carriedby the inner end of the shank Z4 and is adapted to abut against the inner end of the sleeve 25.

Theshank 24, within the housing Ill, has secured thereto a head 2l against which the sphere i8 is adapted to engage when the housing I0 is tilted either laterally or longitudinally. A spring 25 is interposed between the head 21 and the sleeve 25 so as to constantly urge the movable contact 23 to circuit breaking position. A second contact 29 is slidably carried by a stud 35 which is insulated by insulating means 3| from the outer end of the housing 22. The stud 30 is formed with a reduced diameter bore 32 and is also provided with a larger diameter bored-3 3 extending from the outer end of the bore 32, and within which a head 34 carried by the outer contact 29 is adapted to slidably engage. A cap 35 is mounted on the outer end of the studs!) and has secured thereto a threaded shank 36 on which a terminal nut 31 is threaded. A spring 38 is disposed in. the bore 33, bearing at its outer end against the cap 35 and hearing at its inner end against the head 3 The spring 33 provides a cushioning means to cushion the shock caused by engagement of contact 23 with contact 2 9.

The terminal nut 3'! is adapted to secure one end of a conductor 39 to the switch 20, and the conductor 39 is adapted at the opposite end thereof to be connected to a magneto forming the source of electric current supply for the tractor engine or the like. A second conductor fit is connected to the housing it and is also connected to the ground so that when the ball crsphere I3 engages one of the switch members, that is, either one of the switches 29 extending laterally from the housing or the rear switch 2| the electric circuit of the magneto which is connected to the ignition system of the engine will be grounded. In practice the housing is mounted either on the engine or vehicle chassis and is grounded thereby.

to disclosed modified 'forrn of this invention for use in a battery type ignition circuit. The housing is constructed similar to the housing Iii, but in place of the normally open switches used in the magneto circuit, a normally closed switch 41 is provided and is interposed. at any suitable point in the ignition, such as between the high tension coil and the distributor. The switch 4! comprises a contact 42 which is carried by a resilient strip or carrier 43 connected to a terminal 44 which is grounded to the housing Illa. A second contact 45 is disposed in confronting position to and normally engages contact 42. Contact 45 is connected to a terminal 46 which is insulated from housing The ball upon engagement with contact carrier 43 will bend the carrier outwardly and disengage contact 42 from contact 45.

In Figure 6 there is dis-closed a single type of enclosed switch structure embodying a tubular housing a1 within which a ball switch operator similar to ball i3 is loosely mounted. A switch 201) formed as switch is mounted in one end of the housing 41 and is interposed in the magneto ignition circuit. The housing 41 is adapted to be mounted on an inclination to the vertical so that the ball operator will normally engage in the rounded end of the housing. The housing 41 is mounted either on the engine or fixed to the frame or body oi the vehicle. ing 41 is elongated and free from obstructions interiorly thereof to permit the unobstructed sliding or rolling of a ball therein. The switch 2% is constructed in every detail as the switch 26 described above. As only r vided at one end of the housing A! this switch will be actuated by the excessive tilting of the tractor in one direction along the length of the housing. Aside from the shape of: the housing 41 and the mounting of but one switch therein, the use and operation of the switch shown in Figure 6 is the same as the use and operation of the switch shown in Figures 1 to iwhen tilting the tractor in any one direction.

In the use and operation of the switch shown in Figures 1 to 5, the housing ll! is adapted to be secured to a suitable bracket or other atmeans and mounted on the tractor in a substantially horizontal position. The tractor may be used in the normal manner but when the tractor tilts laterally to a predetermined degree, depending on the angle formed by the two divergent sides of the bottom H, the ball 18 will roll laterally by gravity and will engage one of the heads 2? which is lowermost. of the ball [3 with a lower head 2'! will cause this head to move outwardly so that contact 23 will engage contact 29. At this time the ignition circuit in which the magneto is interposed will be grounded and the engine will stop.

In the event the tractor is moved forwardly and upwardly over hilly ground, and the inclination of the tractor exceeds a predetermined dangerous angle, or if the tractor is under heavy pull on level ground causing the front end to rise on? the ground beyond a predetermined dangerous angle, the ball is will roll rearwardly and downwardly in the angle formed by the divergent bottom sides H, and will strike the rear switch. The switch will thereupon be closed so that the 1 actor cannot move forwardly until the of the tractor has been changed.

With a switch as hereinbefore described, a conventional tractor will be insured against tip ping over, either laterally or rearwardly so that the tractor will not be damaged by tipping over either rearwardly or laterally and the operator The house switch is pro Engagement all) will not be injured. This safety switch can be constructed at small cost and being sealed as to the switch operator, the switch will not get out of order, and as soon as the tractor has the angle reduced from a dangerous angle to a lesser safe angle, the switch operating ball [8 will roll toward the center of the housing, and spring 28 will move contact 23 out of engagement with contact 29.

I do not mean to confine myself to the exact details of construction herein disclosed, but claim all variations falling within the purview of the appended claims.

What I claim is:

1. An enclosed safety switch adapted to be interposed in an ignition circuit comprising a housing mounted with at least the lower wall thereof inclined relative to the horizontal, said housing having a high end formed as an extension thereof, a normally open switch carried by the high end of said housing and enclosed by said extension, said switch including a fixed contact resiliently mounted on said end, and a movable contact carried by a plunger slidably mounted in said extension and normally resiliently biased inwardly of said housing, and a plunger actuating member movably disposed in said housing and normally positioned at the low end thereof and adapted, upon raising of said low end above a horizontal plane passing through said normally high end, to move along said lower wall towards said normally high end to engage said plunger for closing said switch.

2. An enclosed safety switch adapted to be interposed in an ignition circuit comprising an elongated tubular housing having the opposite ends thereof closed and adapted to be mounted with the longitudinal axis thereof inclined relative to the horizontal, a high end of said housing having a sleeve-like extension extending outwardly thereof, said extension having an axial bore communicating with and centered. relative to the bore of said housing, a normally open switch carried by said extension having an enclosed contact spaced from a plunger member slidably extending into the housing, said plunger being positioned to engage said enclosed contact when depressed to close said switch, and a spherical member loosely disposed within said housing and normally positioned at the low end thereof and adapted, when said low end is raised above a horizontal plane passed through said normally high end, to roll along said housing towards said normally high end to depress said plunger for closing said switch.

ESTEL M. WARREN.

REFERENCES CITED The following references are of record in th file of this patent:

UNITED STATES PATENTS Number Name Date 1,393,312 Perry Oct. 11, 1921 1,633,386 Rutledge 11 June 21, 1927 2,456,799 Smies Dec. 21, 1948 FOREIGN PATENTS Number Country Date 377,872 Germany June 28, 1923 741,298 France Dec. 3, 1932 

